Reducing composition useful for textile printing, dyeing, and other purposes



Patented Mhy 14, i940 REDUCING COMPOSITION USEFUL FOB TEXTILE PRINTING,DYEING, AND OTHER 7 PURPOSES Jacob Katz, Providence, a: 1., assignor toWarwick-hemioal Company, West Warwick, R. I., acorporation of RhodeIsland Noni-swing. Application August 29, 1939, Serial Nr 292.411

14 Claims.

The present invention relates to reducing compositions and particularlyrelates to reducing compositions which may be utilized in connectionwith textile printing and dyeing procedures and for other purposes wherea predetermined oxidation-reduction potential is to be maintained.

. In certain types of printing known to those skilled in the arts asdischarge printing, it is the custom to dye the cloth or fabric withcertain types of dyestuffs which may be reduced to a colorless, solubleform and to imprint or place paste or viscous liquid containing asoluble reducing agent in a suitable design or pattern upon the dyedfabric and subsequently to dry, age and wash, whereby a white figure ordesign may be produced on the colored cloth. Or if it is desired, acolored figure or design may be produced instead of the white figure ordesign by addition of suitable colors, not affected by the reducing goagent, to the printing paste or liquid. For instance, a dark navy blueshade may be dyed on a fabric and then discharged to a clear whitedesign or merely to a light blue by using less reducing agent. Qr in theevent that itmay be 25 desirable to imprint" a black figure on a navyblue ground, the black color or pigment may be mixed with the printingcomposition containing the reducing agent. i

"It is also, custoinary in many cases to print 30 with a compositioncontaining a normally insoluble dyestufl" which has been reduced to asoluble or leuco condition by inclusion in the printing paste of areducing agent. After printing the dye and reducing agent are oxidizedwith result- 35 ant deposition of the insoluble dyestufi.

Hydrosulphites and sulphoxylates are widely used as such reducing agentsin textile printing procedures, particularly to cause development ofcolor or discharge of color in connection with 40 indigoid,anthraquinone, carbazol, sulphur and vat coloring matters in general.These hydrosulphites or sulphoxylates also are used in other processesand industries because of their reducing characteristics.

45 However, hydrosulphites and sulphoxylates and their derivatives havemany disadvantageous characteristics. They are not most stable compoundsand tend to decompose or change in strength standing in air and/or atelevated tem- 50 peratures, Moreover, they must be taken up in solutionor employed in vcombinations withquantities of hygroscopic materials oragents which will maintain a moist condition when utilized in varioustextile printing-or discharge 55 procedures. Hygroscopic agents, such asglycerol, glycol and sugars increase the cost of processing the textilematerial. I g

It is, therefore, among the objects of the present invention-to provideimproved reducing compositions'of the character above described'which 5may be more conveniently used in connection withdyeing and printing oftextiles or for many other purposes where the inclusion of a reducingagent has been found desirable or necessary.

Still further objects and advantages will appear 10 from the moredetailed description set forth. below, it being understood, however,that this more detailed description is given by way of illustrationsince various changes therein may be made by those skilled in the artwithout depart- 15 ing from the scope and spirit of the invention.

It has been found that most satisfactory reducing compositions,particularly for use in processes where dyes are to be reduced intextile printing, dyeing and stripping, may'be produced by'heatingtogether various carbo-hydrates and particularly water solublecarbo-hydrates or sugars with reducing sulphur. compounds andparticularly with compounds of sulphurous acid.

It has been found that when various sugars, preferably sucrose orcrudemixtures containing the same, and less preferablydextrine, glucose,fructose, black strap molasses, and so forth, are heated with sulphitesand particularly with alkali metal or alkali earth metal sulphites underpressure and under acid conditions a most effective material isproduced. i I

This reaction is preferably carried out in an autoclave or closedpressure vessel at pressures varying from to 15 atmospheres, preferablysubstantially above atmospheric, and at temperatures ranging from 50-to150 C preferably about 110 C. i

Preferably, suflicient acid or acid materials such for example assulphuric acid, phosphoric 40 acid, boric acid, sulfuryl chloride,phosphorous oxychloride, and so forth, are added to give a pHvaryingfrom 1 to 4, and desirably around 2 or 3.

There apparently results a complex mixture containing various types ofcarbo-hydrate derivatives formed by the direct sulfonation of thehydroxy groups of the carbo-hydrate by the reducing sulfur compounds.The resulting prod-, uct consists of a very small quantity of unreactedcarbo-hydrate, and larger quantities of the following compounds as suchor their sulfur derivatives-polyhydroxy alcohols, .ketoand aldocompounds, polymerization products, aldols, acetals, etc., all of whichappear to act most efiectively'tojgether as a reducing agent, particula'rly 'when'the complex mixture has been neutralized.

The reaction mixture produced may be di- I phites and/or sulphoxylatesto form textile printing, dyeing-and stripping compositionsr: r.

The solution which is prepared is most effective when it contains asubstantial amount of water and it is found most. satisfactory to havethe solid content range from about 40 to .60% concentration with anoptimum oi about.50% con centration, which will not take up water fromthe air nor evaporate andwhich solution may be stored for long periodsof time and utilized when convenient without special storage apparatus.

The composition may be used in printing pastes and in dye baths wheredyes are to be reduced to soluble or leuco'form and it may be veryconveniently combined with vat colors selected from the group consistingof indigoid colors, sulphur, anthraquinone colors and carbazol colorsand with thickening agents such as British gum, gum

shiraz, gum tragacanth, dextrin, gum arabic,

starch, pectin, methyl cellulose without any un- 'desirable efl'ect uponthe properties of such agents. a 1

- Although the composition when mixed with 'hydrosulphite orsulphoxylate has a relatively higher reducing action and much higher inmany respects than hydro-sulphite or sulphoxylate itself, nevertheless,it is not oxidized by air and does not substantially lose its reducingpower as do the latter compounds, although it be exposed to air overlong periods of'time. This is particularly advantageous because in theprinting operations it is at times necessary for the goods I to lay overbetween the printing and ageing operations. Where sulphoxylates andhydrosulphites are used alone as the reducing medium this laying overcauses a variation in the shade because they may oxidize prematurely.

The reducing composition is specially advantageous since it has a muchgreater potential reducing power than hydrosulphites and sulphoxylatesalone and at the same time will reduce at a slower rate.

The reducing composition may also be utilized at a wide variety of pI-Isand alkaline materials such, as sodium or potassium carbonate, potassiumand sodium hydroxides, or mixtures of each and potash and soda ash maybe included in the printing composition without any untoward eil'ect.

It is also readily possible to include moistening agents, such asglycerin, glycols, sugars and so forth, in the printing-compositionwithout affecting the reducing agent.

Among the suitable base compositions which may be utilized for carryingthe unreduced or pre-reduced color and/or the reducing composition isone containing about four pounds of British gum, two pounds ofcornstarch, one eighth gallon of glycerol and two and one quarter poundsof potassium carbonate which is made up to three gallons with water.

The amount of water may be readily controlled to determine the finalviscosity or pasty character of the mixture.

For example, to such a composition there may be added from 5 to 20% of a50% solution of reducing composition and a suitable amount of vat onehalf color to obtain the d fiired shadeontintor depth or color.

The printing paste may be kept for along time with assurance that thereducing composition will not cause any undesirable disintegration ordeterioration therein.

As an example of one method of producing a reducing mixture to which theinvention is -by no 'mans restricted, 678 pounds of water may beintroduced into a glass lined 500 gallon tank and 588 parts of sucrosemay be dissolved therein.

Thenthe mixture may be heated for about an hour with stirring todissolve the sugar.

Then, 234 pounds of sodium acid sulphite is added and the pressure isincreased from 5 to 10 pounds per square inch, and this pressure ismaintained for about one half hour.

The temperature is then permitted to drop to atmospheric with or withoutwater cooling and the pressure is permitted to drop to about four poundsover the course of several hours.

The mixture is finally neutralized with caustic sodium or potash ortriethanolamine.

The reducing mixture may then be immediately utilized with othermaterials in textile procedures.

As another example, a reaction mixture of 86 /2 pounds of water, 76pounds of sucrose and 30 pounds of sodium acid sulphite may be providedand placed in a closed vessel.

The temperature is then elevated to 240 F.

vwith a pressure of ten pounds per square inch which pressure andtemperature are maintained for one to two hours.

Then, the mixture is cooled until the pressure drops to five pounds andwhen it is cold about 67 pounds of acetone is added.

The pressure then may be brought up to pounds per square inch for aboutfour hours with heating and the, mixture maybe permitted to cool forthirty six hours until it gets down to room temperature.

The product is neutralized, then withdrawn from the vessel and may beutilized as a, reducing agent.

The reducing composition may also be utilized in connection withbleaching compositions, washing compounds, foodstuffs, coatingcompositions. leather treating compositions, paper impregnatingcompositions and in many other connections where it is desirable to havea reducing agent present during a course of treatment.

Although the reducing agent may be "utilized by itself in textileprocessing it is preferably used to replace part of the hydro-sulphiteor sulphoxylate and it may be used in combination with hydrosulphites,sulphoxylates, their formaldehyde derivatives or zinc, calcium ormagnesium salts of such derivatives in substantially equal parts byweight' By the expressions vat dye or vat coloring matters as used inthe present specification, are included indigoid, anthraquinonecarbazol, sulphur, and other d-yes which are reduced or rendered solublewith a reducing composition before or after application to the fabric ortextile material.

It is to be understood that many changes in the proportions, ingredientsand treating conditions may be made without departing from the scope ofthe invention and it is intended to include all such alternativemodifications and variations as come within the scope of the appendedclaims.

mospheres.

2. A textile coloring composition comprising a vat dye and a reducingcomposition formed by the reaction of a water soluble carbohydrate and areducing sulphurous acid salt at a temperature varying between about 50and 150 C., and at a pressurevarying about between V; and 15atmospheres. V

3. A textile coloring composition comprising a vat dye and a reducingcomposition formed by the reaction of a water soluble carbo-hydrate andan alkali metal sulphite at a temperature varying between about 50 and-L150 C.,-and a pressure varying about between and 15 atmospheres.

4. A method of making a-textile treating composition for use in dyeingand in processes wherein dyes are reduced to soluble, leuco, orcolorless compounds which comprises reacting together a water solublecarbo-hydrate and a reducing sulphur acid salt under heat and pressureat a temperature varying between about 50 and 150 0., and a pressurevarying about between and 15 atmospheres. 1 ,5. A method of ma 'ng atextile treating composition for use in dyeing and in processes whereindyes are reduced to soluble, leuco, or colorless compounds whichcomprises reacting together a water soluble carbo-hydrate and a salt ofsul-' phurous acid under heat and pressure at a tem- I 6.,

perature varying between about 50 and150 and a pressure varying aboutbetween V, and 15 atmospheres. q

6. A textile treating composition for use in dyeing and in processeswherein dyes are reduced to soluble, leuco, or colorless compoundscomprising the heat and pressure reaction products of a water/solublecarbo-hydrate and a reducing sulphur acid compound at a temperaturevarying betweenabout and I varying about between V; and 15 atmospheres.

'7. Asa textile printing composition comprising a thickening agent and areducing composition formed by the reaction of sugar and a bisulphiteunder heat and pressure, said heat Y varying from about 50 C4 and apressure varying from about 50 to 150 0., and said pressure varying fromabout A to 15 atmospheres.

8. A textile printing composition comprising British gum and a reducingcomposition formed by the reaction of sugar and a bisulphite under heatand pressure, said heat varying from about 50 to 150 0., and saidpressure varying from about A to 15 atmospheres.

9. A printing composition comprising a vat color, British gum, areducing composition formed by the reaction of sugar and a bisulphiteunder heat and pressure, cornstarch, glycerol, and potassium carbonate,said heat varying from about 50 to 150 0., and said pressure varyingfrom about /z to 15 atmospheres.

10. A process of printing textiles which comprises treating suchtextiles with a printing composition containing a reducing compositionformed by the reaction of sugar and a bisulphite under heat andpressure, said heat varying from about 50 to 150 C., and said pressurevarying from about A to 15 atmospheres.

11, A process of printing textiles which comprises treating suchtextiles with a printing composition containing a reducing *compositioniormed by the reaction of sugar and a bisulphite under heat andpressure, said heat varying from about 50 to 150 C., and said pressurevarying from about /2 to 15 atmospheres.

13. A process or printing textiles which comprises treating suchtextiles with a printing composition containing a reducing compositionformed by the reaction of sugar and a bisulphite under heat andpressure, a 'vat color, a thicken ing agent and potassium carbonate,said heat to 150 0., and said pressure varying from about /2 to 15atmospheres.

13. A vat dyeing composition comprising a vat dye and a reducingcomposition formed by the reactibn of sugar and a bisulphite under heatand pressure, said heat varying from about 50 to 150 0., andsaidpressure varying from about 5 2 to 15 atmospheres. v a

, 14. A process of producing vat dyes which comprisess reacting said vatdyes in .aqueous media with 'a reducing composition including the

